Power-assisted tissue aspiration instrument with cauterizing cannula assembly

ABSTRACT

A method and apparatus is disclosed for mechanically-assisted liposuction treatment. The apparatus includes a hand-holdable housing, an electro-cauterizing cannula assembly, and a reciprocation mechanism. The hand-holdable housing has a cavity adaptable for receipt of a portion of the electro-cauterizing cannula assembly. The electro-cauterizing cannula assembly includes an inner cannula and an outer cannula, each having a distal end and a proximal end and at least one aspiration aperture about the distal end. The inner cannula is disposed within the outer cannula and the inner and outer aspiration apertures are in at least partial registration to form an effective aspiration aperture. The reciprocation mechanism is disposed within the housing and is operably associated with either the inner or outer cannula so that one of the cannulas can be selectively caused, to reciprocate relative to the housing while the other is stationarily disposed relative to the housing. As one of the cannulas is caused to reciprocate relative to the other the effective aspiration aperture formed through the distal end of the cannula assembly, is caused to undergo periodic displacement. During aspiration of tissue, high-voltage RF power signals are supplied to the inner and outer cannulas to effect hemostasis about the reciprocating aspiration aperture. Such hemostasis is achieved by causing protein molecules within aspirated tissue to coagulate in response to the high-voltage RF signals being supplied across the reciprocating cannulas. In the preferred embodiments, the amount and rate of such aspiration aperture displacement is controllably adjustable. The cannula assembly is releasably detachable from the hand-holdable housing to facilitate cleaning and sterilization of the cannula assembly and the housing.

RELATED CASES

The present Application is a Continuation of application Ser. No.08/976,073, filed Nov. 21, 1997, now U.S. Pat. No. 6,346,107, which is aContinuation-in-Part of application Ser. No. 08/882,927 filed Jun. 26,1997, now U.S. Pat. No. 5,795,323, which is a Continuation ofapplication Ser. No. 08/307,000 filed Sep. 16, 1994, now U.S. Pat. No.5,643,198, which is a Continuation of application Ser. No. 07/627,240filed Dec. 14, 1990, now U.S. Pat. No. 5,348,535. Each said Applicationis incorporated herein by reference as if set forth in its entirety.

FIELD OF INVENTION

The present invention relates generally to a method and apparatus forperforming liposuction and more particularly to a method and apparatusfor performing liposuction in a mechanically assisted manner usingpowered expedients.

BRIEF DESCRIPTION OF THE PRIOR ART

Suction lipectomy, commonly known as liposuction or lipoxheresis, is awell known surgical procedure used for sculpturing or contouring thehuman body to increase the attractiveness of its form. In general, theprocedure involves the use of a special type of curet known as acannula, which is operably connected to a vacuum source. The cannula isinserted within a region of fatty tissue where removal thereof isdesired, and the vacuum source suctions the fatty tissue through thesuction aperture in the cannula and carries the aspirated fat away.Removal of fat cells by liposuction creates a desired contour that willretain its form.

Presently, there are two widely accepted techniques of liposuction andeach may be practiced using a conventional liposuction cannula. Thefirst and most common method proposed by Yves-Gerard Illouz anddescribed in the paper “Illouz's Technique of Body Contouring byLipolysis” in Vol. “I, No. 3, July 1984 of Clinics in Plastic Surgery,involves making regular tunnels at a depth of at least 1 centimeterunder the skin. According to this method, one or two insertions aremade, with radial excursions of the cannula into the fatty tissue of thepatient. The result is a multitude of concomitant sinuses formed belowthe subcutaneous fatty tissue, leaving intact as far as possible theconnections between the skin and underlying tissue, thereby retainingthe blood vessels, the lymphatics and the nerve endings. The secondmethod is the original liposuction procedure proposed by U. K.Kesselring, described in “Body Contouring with Suction Lipectomy”, inVol. 11, No. 3, July 1984, Clinics in Plastic Surgery. According to thetechnique, an entire layer of regular, deep fat is removed by aspirationthrough the cannula, leaving a smooth, deep surface of the residualpanniculus. The space thus created is then compressed, optimallyfollowed by skin retraction.

Both of these prior art liposuction techniques require that the surgeonpush and pull the entire cannula back and forth almost twenty times foreach insertion made. Typically, twenty to thirty tunnels are made. Thisis necessary to ensure even removal of fat in the targeted region.During this procedure, the surgeon typically massages the flesh in thearea of the aperture in the cannula, while at the same time, thrustingthe rod in and out of the tunnel. Due to the trauma involved during theprocedure, the patients' skin, turns black and blue for several weeks.Due to the physically exacting nature of the procedure, the surgeontypically comes out of an operating room extremely tired and suffersfrom muscular fatigue which prevents him from performing, for some timethereafter, the delicate operations involved, in ordinary plasticsurgery.

Recently, the use of a “guided cannula” has been proposed by R. de laPlaza, et al., described in “The Rationalization of Liposuction Toward aSafer and More Accurate Technique,” published in Vol. 13, AestheticPlastic Surgery, 1918 9. According to the technique, a cannula is usedin conjunction with an outer guide sheath through which the cannula canslidably pass while held in place by the handle portion of guide sheath.Once the cannula and its sheath have been introduced into the fattytissue, the sheath guide remains in the tunnel and guides successiveintroductions of the cannula, keeping it in the same tunnel. While theuse of this liposuction technique offers some advantages over theconventional unguided liposuction cannulas, the guided cannulanevertheless suffers from several significant shortcomings anddrawbacks. In particular, the guided cannula requires manually thrustingthe cannula through the guide sleeve repeatedly for each tunnel.Although this is a less physically demanding procedure, the surgeon mustthrust the cannula even more times through each tunnel to achieve thedesired effect and hence is still easily fatigued and prevented fromperforming, for some time thereafter, the delicate operations involvedin ordinary plastic surgery.

In an attempt to solve the above-described problem, U.S. Pat. Nos.4,735,605, 4,775,365 and 4,792,327 to Swartz disclose an assistedlipectomy cannula having an aspiration aperture which effectivelytravels along a portion of the length of the cannula, thereby obviatingthe necessity of the surgeon to repeatedly push the cannula in and outof the patients' subcutaneous tissue where fatty tissue is to beremoved. While this assisted lipectomy cannula can operate on either airor electric power, it nevertheless suffers from several significantshortcomings and drawbacks. In particular, the device requires an outertube with an elongated slot and a inner tube having a spiral slot whichmust be rotated inside the outer tube to effectuate a travelingaspiration aperture. In addition to the device's overall constructionposing difficulties in assembly, cleaning and sterilization, use with avariety of cannulas and highly effective fat aspiration does not appearpossible.

Accordingly, there is a great need in the art for a mechanicallyassisted, lipectomy cannula which overcomes the shortcomings anddrawbacks of prior art lipectomy apparatus.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

Thus, it is a primary object of the present invention to provide animproved method and apparatus for performing liposuction which assiststhe surgeon in the removal of fat and other subcutaneous tissue (such asbut not restricted to gynecomastia) from surrounding tissue, withincreased safety and without promoting physical fatigue.

It is another object of the present invention to provide such anapparatus in the form of a hand-holdable liposuction instrument, havinga cannula assembly, in which the location of the aspiration aperture isperiodically displaced as the inner or outer cannulas undergo a slidingmovement relative to the hand-holdable housing.

It is a further object to provide such a liposuction instrument in whichthe rate of reciprocation and the amount of excursion of the aspirationaperture, are selectively adjustable by the surgeon during the course ofoperation.

An even further object of the present invention is to provide such aliposuction instrument which can be driven by air or electricity.

A further object of the present invention is to provide such aliposuction instrument, in which the cannula assembly can be simplydetached from the hand-holdable housing for ease of replacement and/orsterilization.

An even further object of the present invention is to provide animproved method of performing liposuction, in which one of the cannulasof the cannula assembly is automatically reciprocated back and forthrelative to the hand-holdable housing, to permit increased control overthe area of subcutaneous tissue where fatty and other soft tissue is tobe aspirated.

Another object of the present invention is to provide a power-assistedliposuction instrument, wherein means are provided along the cannulaassembly to effect hemostasis during liposuction procedures and thelike.

Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein the hemostasis means isrealized using RF-based electro-cauterization.

Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein RF-basedelectro-cauterization is carried out by providing electro-cauterizingelectrodes along the cannula assembly and supplying to these electrodesRF signals of sufficient power to achieve electro-coagulation and thushemostasis during liposuction procedures.

Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein the outer cannula isrealized from a non-conductive material and electro-cauterizingelectrode elements are inserted within the aspiration apertures thereofand electrical wiring embedded along the outer cannula and connected toa contact pad embedded within the base portion thereof, and wherein theinner cannula is made from an electrically conductive material whichestablishes electrical contact with contact brushes, mounted within thecentral bore of the base portion of the inner cannula.

Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein RF supply and returnsignals are coupled to the cannula assembly by way of the base portionof the outer cannula.

Another object of the present invention is to provide a power-assistedliposuction instrument, wherein RF-based electro-cauterization isrealized using electrically conductive inner and outer cannulas whichare electrically isolated by way of thin Teflon coatings applied to theouter surface of the inner cannula and/or the interior surface of theouter cannula.

Another object of the present invention is to provide a power-assisted,liposuction instrument, wherein ultrasonic energy of about 50 KHZ iscoupled to the inner cannula in order to effect protein coagulationabout the aspiration apertures and thus achieve electro-cauterization(i.e., hemostasis) during liposuction procedures.

Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein such ultrasonic energy isproduced by piezoelectric crystals embedded within the base portion ofthe inner cannula and driven by electrical signals having a frequency ofabout 50 KHZ.

Another object of the present invention is to provide such a liposuctioninstrument, wherein the electrical drive signals are supplied to thepiezoelectric transducers by way of a pair of electrically conductiverails embedded within the interior surface of the cannula cavity of thehand-holdable housing of the liposuction device.

Another object of the present invention is to provide a way of carryingout RF-based cauterization within a cannula assembly, wherein theoperating surgeon is enabled to perform lipolysis by driving thepiezo-electric transducers within the base portion of the inner cannulawith signals in the frequency range of about 20-25 KHZ.

These and other objects of the present invention will become apparenthereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of, the objects of the present, invention,reference is made to the detailed description of the illustrativeembodiments which are to be taken in connection with the accompanyingdrawings, wherein:

FIG. 1A is a perspective view of a first embodiment of the liposuctiondevice of the present invention;

FIG. 1B is a cross-sectional view of the liposuction device of thepresent invention taken along line 1B—1B of FIG. 1A;

FIG. 1C is an elevated end view of the liposuction device of the presentinvention illustrated in FIG. 1A, showing the electro-cauterizingcannula assembly thereof retained within the cannula cavity of itshand-holdable housing, and alternatively with the hingedly connectedhousing cover panel disposed in an open position for removal of thecannula assembly therefrom;

FIG. 2A is a perspective, partially broken away view of theelectro-cauterizing, cannula assembly of, the present inventioninstalled in the liposuction instrument of FIGS. 1A through 8C, in whichthe electrically-conductive inner cannula is adapted to freely undergosliding movement within the stationary electrically non-conductive outercannula while electro-cauterization is performed about the aspirationapertures thereof under the control of the surgeon;

FIG. 2B is a perspective view of the distal end of the inner cannulashown in FIGS. 1A, 1B and 2A;

FIG. 2C is a cross-sectional view of the electrically-conductive innercannula taken along line 2C—2C of FIG. 2B;

FIG. 2D is a perspective, partially broken away view of the electricallynon-conductive outer cannula shown in FIGS. 1A, LB and 2A;

FIG. 2E is a cross-sectional, view of the electro-cauterizing assembly,taken along line 2E—2E of FIG. 2A;

FIG. 2F is a cross-sectional view of the base portion of theelectro-cauterizing cannula assembly of the present invention takenalong line 2F—2F in FIG. 2A.

FIG. 3A is a plan view of a cauterizing electrode of the presentinvention adapted for insertion within the elongated aperture of theelectrically non-conducting outer cannula;

FIG. 3A1 is an elevated side view of the cauterizing,electrode of thepresent invention taken along line 3A1—3A1 of FIG. 3A;

FIG. 3A2 is an elevated side view of the cauterizing electrode of thepresent invention taken along line 3A2—3A2 of FIG. 3A.1;

FIG. 3B is a perspective view of the electricallyconductive collar andbrush device of the present invention which inserts with the centralbore formed in the base portion of the electrically non-conductive outercannula of the present invention shown in FIG. 2D;

FIG. 3B1 is a cross-sectional, view of the electricallyconductive collarand brush device of the present invention taken along line 3B1—3B1 ofFIG. 3B;

FIG. 4A is a cross-sectional view of a portion of a second embodiment ofthe liposuction device of the present invention, illustrating analternative outer cannula retention means;

FIG. 4B is a cross-sectional view of a portion of a second embodiment ofthe liposuction device of the present invention, illustrating analternative inner cannula retention means;

FIG. 5 is a cross-sectional view of third embodiment of the liposuctiondevice of the present invention, illustrating a means for controllingthe mount of excursion of the aspiration aperture along the cannulaassembly;

FIG. 6A is a cross-sectional view of a sixth embodiment of theliposuction device of the present invention, illustrating the use of apair of gas driven piston-type motors and a mechanically-operated gasflow control device disposed in its first state of operation;

FIG. 6B is a cross-sectional view of the liposuction device of thepresent invention taken along line 6B—6B of FIG. 6A;

FIG. 6C is a perspective view of the preferred embodiment of themechanically-operated gas flow control device illustrated in FIG. 6A;

FIG. 6D is a cross-sectional view of the gas flow control device of thepresent invention taken along line 6D—6D of FIG. 6C.

FIG. 7A is a perspective, partially broken away view of a secondsnap-fit type inner cannula intended for use with the second embodimentof the liposuction device of the present invention;

FIG. 7B is a cross-sectional view of the outer cannula of the presentinvention taken along lines 7B—7B of FIG. 7A;

FIG. 8 is a perspective, partially broken away view of a snap-fit typeouter cannula intended for use in connection with the second embodimentof the liposuction device of the present invention;

FIG. 9A is a plan cross-sectional view of a seventh embodiment of theliposuction device of the present invention, having a hand-holdablehousing realized in the form of a pistol-shaped structure havingdetachable barrel and handle portions;

FIG. 9B is a cross-sectional, partially broken away view of theliposuction device of the present invention taken along line 9A—9B ofFIG. 9A, showing the cam mechanism of the present invention;

FIG. 9C is an elevated cross-sectional view of the liposuction device ofthe present invention, taken along line 9C—9C of FIG. 9A, showing theinner cannula disposed at a first position within the cannula cavity ofthe hand-holdable housing, and the rotary motor and speed control unitin the handle portion thereof;

FIG. 9D is a cross-sectional view of a portion of the inner cannulaexcursion control means shown in FIGS. 9B and 9C;

FIG. 9E is a cross-sectional view of the liposuction device of thepresent invention taken along line 9E—9E of FIG. 9A, showing the rotarydrive wheel of the cam mechanism in operable association with theactuation element which projects through the cannula cavity and isengaged in the slotted base portion of the inner cannula, and alsoshowing in phantom lines the cover panel of the barrel portion disposedin an open configuration permitted insertion or removal of the inner andouter cannulas of the present invention;

FIG. 9F is an elevated partially broken away rear view of the barrelportion of the liposuction device taken along line 9F—9F of FIG. 9A;

FIG. 10 is a cross-sectional view of another illustrative embodiment ofthe liposuction device of the present invention, wherein a liposuctiondevice of the present invention is provided, having a double-actingair-powered cylinder with a magnetically-coupled actuator and whereinthe electro-cauterizing cannula assembly of the present invention isinstalled;

FIG. 10A is a cross-sectional schematic diagram of the air flow controldevice employed in the liposuction device shown in FIG. 10, in which thecontrol valve thereof is mechanically-linked to the reciprocating pistoncontained within the cylinder-style reciprocator within the housing ofthe liposuction device;

FIG. 11A is a perspective, partially broken away view of a theelectro-cauterizing cannula assembly of the present invention in theliposuction instrument of FIG. 10 in which the electrically-conductiveinner cannula is adapted to freely undergo sliding movement within thestationary electrically non-conductive outer cannula whileelectro-cauterization is performed about the aspiration aperturesthereof under the control of the surgeon;

FIG. 11B is a perspective view of the distal end of the inner cannulashown in FIG. 11A;

FIG. 11C is a cross-sectional view of the electrically-conductive innercannula taken along line 11C—11C of FIG. 11B;

FIG. 11D is a perspective, partially broken away view of theelectrically non-conductive outer cannula shown in FIG. 11A;

FIG. 11E is a cross-sectional view of the electro-cauterizing cannulaassembly taken along line 11E—11E of FIG. 11A;

FIG. 11F is a perspective view of the base portion of theelectrically-conductive inner cannula shown in FIG. 11 showing anelectrical contact pad embedded in the outer surface thereof forconducting the conductive rail embedded in the wall surface of thecannula cavity;

FIG. 11G is a cross-sectional view of the liposuction instrument takenalong line 11G—11G of FIG. 10;

FIG. 12A is a plan view of a cauterizing electrode of the presentinvention adapted for insertion within the elongated aperture of theelectrically non-conducting outer cannula shown in FIG. 11;

FIG. 12A1 is an elevated side view of the cauterizing electrode of thepresent invention taken long line 12A1—12A1 of FIG. 12A, FIG. 12A2 is anelevated side view of the cauterizing electrode of the present inventiontaken along line 12A2—12A2 of FIG. 12A1;

FIG. 13A is a perspective, harshly broken away view of theelectrically-conductive outer cannula employed in an alternativeembodiment of the electro-cauterizing cannula assembly utilizable in theliposuction device of the present invention with suitable modifications;

FIG. 13B is a perspective view of a distal end of the inner cannulashown in FIG. 13A;

FIG. 13C is a cross-sectional view of the electrically conductive innercannula taken along line 13C—13C of FIG. 13B;

FIG. 13D is a perspective, harshly broken away view of the electricallyconductive outer cannula shown in FIG. 13A, over which an electricallyinsulating coating such as teflon is applied to the exterior surfacethereof;

FIG. 14 is a cross-sectional schematic diagram of an alternativeembodiment of the electro-cauterizing liposuction instrument of thepresent invention, wherein the reciprocation means is realized using acylinder-style actuator powered by a supply of pressurized air;

FIG. 14A is a schematic cross-sectional view of the airflow controldevice employed within the liposuction instrument of FIG. 14;

FIG. 14B is a perspective, harshly broken away view of theelectrically-nonconductive outer cannula employed in alternativeembodiment of the elector-cauterizing cannula assembly utilized in theliposuction instrument of FIG. 14;

FIG. 14C is a perspective view of a distal end of the inner cannulashown in FIG. 14B;

FIG. 14D is a perspective, harshly broken away view of the electricallynonconductive outer cannula shown in FIG. 14B, over which anelectrically insulating coating such as teflon is applied to theexterior surface thereof;

FIG. 14E is a perspective view of the base portion of the inner cannulaused in the cannula assembly of FIG. 14B, wherein an electrical contactpad is embedded in the side wall surface of the base portion forengagement with an electrically conductive rail embedded within theinterior wall surfaces of the cannula cavity of the liposuctioninstrument.

FIG. 14F is a cross sectional view of the base portion of the innercannula taken along line 14F—14F in FIG. 14E, showing a plurality ofpiezo-electrical transducers arranged about the lumen of the innercannula for producing and conducting ultrasonic energy signals forpropagation along the length of the inner cannula; and

FIG. 14G is a cross sectional view of the liposuction instrument of FIG.14 taken along line 14G—14G of FIG. 14, showing a pair of diametricallyopposed electrically conductive rails embedded within the interior wallsurfaces of the cannula cavity of the liposuction instrument, whichestablish electrical contact with a pair of electrical contact padsembedded within the base portion of the base portion of the innercannula and are connected to the array of piezo-electric transducersmounted about the outer lumen of the inner cannula.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

With reference to FIGS. 1A through 3D, the first embodiment of theliposuction device of the present invention will be described. Ingeneral, liposuction device 1A comprises a hand-holdable housing 2, adetachable electro-cauterizing cannula assembly 4 having inner and outercannulas 4 and 5, and a reciprocation means 6 for causing inner cannula4 to reciprocate means 6 for causing inner cannula 4 to reciprocaterelative to outer cannula 5, which is stationarily disposed with respectto housing 2. This arrangement effectuates periodic displacement of thegeneral location of aspiration along the cannula assembly through thereciprocating movement of inner cannula 4, while permittingelectro-cauterization of aspirated tissue during operation of theliposuction device.

As illustrated in greater detail in FIGS. 1B, and 2A through 2E, theelectro-cauterizing cannula assembly 3 of the present inventioncomprises an electrically-conductive inner cannula 4 and anon-conductive outer cannula 5, each comprising hollow inner and outertubes with distal and proximal ends 4A, 4B and 5A, 5B, respectively.

As shown in FIGS. 2B and 2C, the outer cannula 5 comprises a hollowouter tube having a distal end 5A and a proximal end 5B. Four outeraspiration (i.e., suction) apertures generally indicated by referencenumerals 8A, 8B, 8C and 8D are provided on the distal end of the innercannula. As shown, elongated apertures generally indicated by referencenumerals 8A, 8B, 8C and 8D are provided on the distal end of the innercannula. As shown, elongated apertures 8A, 8B, 8C and 8D terminate at apredetermined distance away from outer cannula tip 5C, which isessentially blunt for purposes of safety. In general, the length of eachof these elongated outer apertures is substantially longer than thelongitudinal extent of each ratio of these lengths (about 1 to 4);however, in other embodiments, this ratio may differ as desired orrequired in a given application. In a typical embodiment, the length ofthese elongated outer apertures would be within the range of, forexample, two to six inches, commensurate with the amount of displacementto be achieved by each inner aperture.

As illustrated in FIG. 1B, an outer cannula base 17 extends from theproximal end of outer tube 5. The outer cannula base 17 comprises acylindrical structure having a central bore 18, through which distal tip4 and body of inner cannula 4 can freely pass. The outer cannula base 17of the illustrative embodiment includes a flanged portion 19 which fitswithin an annular recess 18 formed in cannula cavity 20 of thehand-holdable housing.

As shown in FIG. 2B, an inner cannula base 10 extends from the proximalend of inner tube 4. As shown, the inner cannula base 10 comprises acylindrical structure having an outlet port 11 formed in its remote end.The inner cannula base 10 of the illustrative embodiment includes anotch or slot 12 formed in its central most portion. As will bedescribed in greater detail hereinafter, notch 12 functions toreleasably receive an extensional portion 13 of actuation element 37, inorder to actuate reciprocation of inner cannula 4 within housing 2. Asillustrated in FIG. 2B, inner cannula 4 has a continuous passageway 14which extends from inner aspiration opening 9 to outlet port 11. Asshown in FIGS. 2B and 2C, the inner aspiration apertures originatebetween the distal tip portion 4C. As shown, elongated apertures 16A,16B, 16C and 16D terminate at a predetermined distance away from outercannula tip 5C, which is essentially blunt for purposes of safety. Ingeneral, the length of each of these elongated inner apertures issubstantially longer than the longitudinal extent of each respectiveouter aperture. In the illustrated embodiment, the ratio of theselengths is about 1 to 4; however, in other embodiments, this ratio maydiffer as desired or required in a given application. In a typicalembodiment, the length of these elongated apertures would be within therange of, for example, two to six inches, commensurate with the amountof displacement to be achieved by each outer aperture with itselectro-cauterizing element.

While not shown, a conventional vacuum source is connected to outletport 11, preferably using optically transparent, semi-flexible tubing15. With this arrangement, aspirated fat tissue can be suctioned throughapertures 8A, 8B, 8C and 8D and opening 9 and transported alongpassageway 14 to a reservoir device (not shown), operably associatedwith the vacuum source.

As illustrated in FIGS. 2A and 2E, electrically-conductive cauterizingelectrodes 160A, 160B, 160C and 160D are inserted about the perimeter ofouter aspiration apertures 16A, 16B, 16C, and 16D, respectively, andfastened thereto by snap-fitting, adhesive or like means. As shown inFIGS. 3A, 3A1, and 3A2, each electrically-conductive electrodecomprises: a sidewall portion 161 which circumferentially extends aboutthe perimeter of the respective aspiration aperture formed in the outercannula; an opening 162 for permitting aspirated tissue and fat and thelike to flow therethrough into the interior of the inner cannula; and acircumferential flange 163 substantially perpendicular to sidewallportion 161 and adapted, to fit within a recessed groove 164 extendingabout the upper outer surface of the respective outer aspirationaperture formed in the electrically non-conductive outer cannula. In theillustrative embodiments, cauterizing electrodes 160A through 160D aremade from stainless steel, brass, gold or any otherelectrically-conductive material that is suitable for contact with humantissue during liposuction and like surgical procedures.

As shown in FIG. 2D, the base portion of the outer cannula is providedwith a pair of spaced apart recesses 165A and 165B for receiving andsecuring a first and second electrically-conductive contact pads 166Aand 166B, respectively. A first groove 167 is formed within the outersurface of the outer cannula 5 and base portion 19 in order to receive afirst length of electrical wiring 168 which establishes electricalcontact between the set of cauterizing electrodes 160A through 160D andan electrically-conductive contact pad 166B. Similarly, a second groove169 is formed within the outer surface of the outer cannula and baseportion 19 in order to receive a second length of electrical wiring 170which establishes electrical contact between the set of cauterizingelectrodes 160A through 160D and second electrically-conductive contactpad 166A. A sealing material such as melted plastic can be used to closeoff the grooves 167 and 169 once the electrical wiring has been recessedwithin the groove. Alternatively, a thin, outer plastic cannula sleevehaving an inner diameter slightly greater than the outer diameter ofouter cannula 4 can be slid thereover and secured to the base portionthereof 19 using screw-threads, snap-fit fastening, ultrasonic-welding,adhesive or the like. When completely assembled, electrically-isolatedcontact pads 166A and 166B are shown in FIG. 2A. It is understoodhowever, that contact elements 166A and 166B can be mounted elsewhere inthe base portion of the outer cannula.

As shown in FIG. 2A, an electrically-conductive collar and brush device171 shown in FIGS. 3B and 3B1 is inserted within the central bore formedin the base portion 19 of the electrically non-conductive outer cannula.The collar and brush device 171 comprises a cylindrical tube 172 madefrom electrically-conductive material (e.g., stainless steel) having anouter diameter that is slightly less than the diameter of the centralbore formed through the base portion of the inner cannula. As shown inFIGS. 3B and 3B1, a pair of diametrically-opposed leaf-like electricalcontact elements 173A and 173B project inwardly from the cylindricalwalls of the device towards its axial center. As best shown in FIG. 2F,the function of electrical contact elements 173A and 173B is toestablish electrical contact between second contact pad 166A (on baseportion 10) and electrically-conductive inner cannula 4 when the innercannula is slid through the central bore 18 of the outer cannula, asshown in FIG. 2A. A small annular flange 174 is formed on one end of thecylinder 172 to delimit the depth of its insertion. A small connectortab 175 is connected to flange 174.

As shown in FIG. 2E, the sidewall portion 161 of each cauterizingelectrode 160A through 160D is of sufficient width (w_(g)) to provide agap region 175 between (i) the electrically-conductive inner/cannula 4adjacent to the electrode and (ii) the sidewall portion 161 thereof.Preferably, the width of each gap 175 is selected so as to minimizeelectrical arcing (i. e. sparking) between each electrode 160 and theelectrically conductive inner cannula 4 when an RF signal of, forexample, about 500 kHZ at 800 Volts is applied thereacross duringelectro-cauterization.

As shown in FIG. 1B, contact pas 166A and 166B establish electricalcontact with conductive elements 176A and 176B embedded in thehand-holdable housing and are embedded within recesses formed in thebase portion 19 of the outer cannula assembly. The conductive elements176A and 176B are connected to the RF supply and RF return signalterminals 177A and 177B of RF generator 178. In the preferredembodiment, RF generator 178 is realized as the Instant Response™Electrosurgical Generator (Model Force FX) by ValleyLab International, asubsidiary of Pfizer, Inc. This Electrosurgical Generator can be easilyconnected to the electro-cauterizing electrodes hereof by electricalcabling 179 in order to drive the same with bipolar outputs producedfrom the Electrosurgical Generator. Notably, the Instant Response™Electrosurgical Generator 178 includes three bipolar output modes,namely: Low/Precise; Medium/Standard; and Macrobipolar.

In order to maintain inner aspiration apertures 8A, 8B, 8C and 8Daligned with outer aspiration apertures 16A, 16B, 16C and 16D,respectively, and thus ensure partial registration therebetween, thedistal end of the inner and outer tubes are provided with a keyingsystem. In the illustrated embodiment, the keying system comprises akeying element 4D disposed on the outer surface of the inner cannula,before distal tip 4C. Keying element 4D can be a rigid or flexibleelement that slides within an elongated outer aperture (e.g., 16B) andprevents axial rotation between cannulas 4 and 5 as they undergorelative reciprocation. To assemble cannula assembly 3, distal tip 4C ofthe inner cannula is inserted through bore 18 in outer cannula base 17so that the distal end of inner cannula 4A is slidably received withinouter cannula 5, as shown in FIG. 3A. In this configuration, keyingelement 4D is received and guided within elongated aperture 8B′ asshown. In this general configuration, cannula assembly 3 is installedwithin cannula cavity 20 by first opening housing cover 21, shown inFIG. 1C. Then outer cannula base flange 17 is inserted;within annularrecess 19 and actuation extension 13 within inner cannula base notch 12.There after, housing cover 21 is closed shut and liposuction device 1Ais ready for operation. A conventional vacuum source is then connectedto outlet port 11, preferably using optically transparent, semi-flexibletubing 15. With this arrangement, fatty tissue, aspirated throughapertures 8A/16B, 8B/16B and 8C/16C and 8D/16D and opening 9, can betransported through passageway 14 to a reservoir device (not shown),operably associated with the vacuum source.

As shown in FIG. 1A, the gross geometry of housing 2 is preferably thatof an ellipsoid; however, other geometries such as, for example, acylindrical structure, can be used in practice in the present invention.Housing 2 contains cannula cavity 20, which extends along the entirelongitudinal extent of the hand-holdable housing. In the illustratedembodiment, cannula cavity 20 has generally cylindrical bearing surfaces22 which match the outer bearing surface 23 of inner cannula base 10, topermit sliding movement of inner cannula 3 within cavity 20. Whilecylindrical bearing surfaces have been selected in the illustratedembodiment, use of other forms of bearing surfaces (e.g., rectangular ortriangular) are contemplated. To minimize friction, bearing surfaces 22and 23 may be coated with a Teflon® or functionally equivalent coating,to facilitate easy sliding of inner cannula base 10 within cavity 20with low wear. As illustrated in FIG. 1B, cannula cavity 20 alsoincludes annular recess 19, into which annular base flange 19 is adaptedto be received in order to render the outer cannula essentiallystationary with respect to hand-holdable housing 2.

As shown in FIG. 1B, electrical contact pads 176A and 176B are embeddedwithin surface-recesses formed within the wall surfaces of the annularrecess 19. Preferably, electrically-conductive contact pads 176A and176B are made from electrically conductive material having a shape whichis similar to the shape of electrically conductive pads 166A and 166Bthat are embedded within the outer surface of the base portion of theouter cannula 5. When the cannula assembly of this embodiment isinstalled within the hand-holdable housing, the electrical contact pads166A and 166B on the base portion of the outer cannula willautomatically establish electrical contact with electrical-contact pads176A and 176B within recess 19, respectively. In this way, the RF supplyand return voltages from RF signal generator 178 are automaticallyapplied to the electro-cauterizing electrodes embedded within thecannula assembly of the present invention.

As illustrated in FIG. 1C, hand-holdable housing 2 is provided with ahinged cover 21. Hinged cover 21 allows cannula cavity 20 to be openedand accessed so that cannula assembly 3 can be selectively installed incannula cavity 20 and removed therefrom as desired or required. Coverpanel 21 has a semi-circular cross-sectional geometry and is connectedto the remaining portion of housing 2 by a conventional hinge means 25.To secure cover panel 21 to the remainder of housing 2, a releasablelocking means 26 is provided at the interface of hinge cover 21 andhousing 2, as shown. Releasable locking means 26 can be realized in avariety of ways, including, for example, using a spring biased clampelement 27 which engages in a notch 28 formed in the external surface ofthe remaining housing portion, as illustrated in FIG. 1C.

In general, there are numerous ways to effectuate reciprocation of innercannula 4 within cannula cavity 20 and thus within stationary outercannula 5. Examples of possible reciprocation means 6 include, but arenot limited to, gas or electrically driven motor(s). In the embodimentsillustrated in FIGS. 1A through 1C, FIGS. 4A through 6A, FIGS. 7 through8A, FIGS. 6A through 6D, and FIGS. 10 through 14D, one or more gasdriven piston-type motors are employed to realize the reciprocationmeans 6 within the liposuction instrument. In the embodiment illustratedin FIGS. 9A through 9F, a rotary-type motor is used to realizereciprocation means 6 of the present invention.

As illustrated in FIG. 1B, a piston-type motor 6 is mounted within amotor cavity 30 provided adjacent to cannula cavity 20 of housing 2.Notably, this reciprocation means cavity 30 extends essentially parallelto cannula cavity 20 and along a substantial portion of the longitudinaldimension of hand-holdable housing as will become more apparenthereinafter. This unique spatial relationship between the cannula cavityand reciprocation means cavity within housing 20, ensures optionalcannula displacement relative to longitudinal dimensions of thehand-holdable housing.

In general, motor 6 comprises a chamber housing 31 having a gas inletport 32 and an inner chamber generally indicated by reference numeral33. Slidably received within the inner chamber of housing 31 is amovable piston 34 having formed in the lower portion wall 35, one ormore gas outlet ports 36. Mounted to the top portion of movable piston34 is actuation element 37, whose extension 13 projects throughlongitudinally disposed slot 38 formed in the bearing wall surface 22 ofcannula cavity 20. As shown in FIG. 1B, actuation extension 13 passingthrough slot 38, is received within notch 12 formed in inner cannulabase 10 and operably associates inner cannula 3 with motor 6.

As illustrated in FIG. 1B, chamber housing 31 is fixedly disposed withinmotor cavity 30. Motor cavity 30 is also provided with at least one port39 for ventilating to the ambient environment, and gas is released frominner chamber 33 upon movable piston 34 reaching its maximumdisplacement or excursion. Movable piston 34 is biased in the directionof chamber housing 31 by way of a spring biasing element 40. Thecompliance of spring biasing element 40 can be adjusted by moving theposition of slidable wall 41 by rotating, for example, threaded element42 passing through a portion 43 of housing 2, as shown. With thisarrangement, adjustment of wall 41, closer to or farther from chamberhousing 31, results in decreasing or increasing, respectively, thecompliance of spring biasing element 40. This mechanism, in turn,provides a simple, yet reliable way in which to control the rate ofreciprocation of movable piston 34, and thus the rate of reciprocationof inner cannula 3 relative to housing 2.

The manner of operation of piston-type motor 6 is described as follows.Gas, such as pressurized air or N₂ gas, is introduced under constantpressure to inlet port 32 of chamber housing 31. As the gas fills up thevolume enclosed by the interior walls of movable piston 34 and chamber33, inner chamber 33 begins to expand, forcing movable piston 34upwardly against the biasing force of spring biasing element 40. Whenmovable piston 34 is displaced sufficiently enough from chamber housing31 so that gas within expanding chamber 33 can be released through gasexit port 39 to the ambient atmosphere, piston 34 will be forced backdownwardly into chamber housing 31. The rate of the forced downwardpiston movement is inversely proportional to the compliance of springbiasing element 40. Subsequently, chamber 33 will again fill up withgas, piston 34 will again be displaced and gas subsequently vented,whereupon reciprocating displacement of piston 34 will be repeated againin a cyclical manner. Since movable piston 34 is operably connected withinner cannula base 10 by way of actuation element 37, this reciprocatingmovement of piston 34 results in reciprocating movement of inner cannula3 within cannula cavity 20. Further, this relative reciprocation betweenthe inner cannula and the outer cannula results in periodic displacementof the effective aspiration apertures along the distal end portion ofthe cannula assembly.

As illustrated in FIG. 1B, the amount of excursion that piston 3 ispermitted to undergo before gas venting and subsequent downward pistonmovement occurs, is determined by the distance “d” defined between gasoutput port 32 and top wall surface 47 of chamber housing 31. A typicalcannula excursion distance of about four inches, for example, willnecessitate that the parameter d, defined above, be also about fourinches.

In FIGS. 4A and 4B, a second embodiment of the liposuction device of thepresent invention is shown. Liposuction device 1B has an alternativecannula assembly retention means a while inhering all of the structuralfeatures of the first embodiment illustrated in FIGS. 1A through 1C. Inparticular, liposuction device 1B does not have a hingedly connectedhousing cover panel, and instead incorporates a snap-fit type cannulaassembly retention mechanism. In accordance with this embodiment,actuation element 37′ has an extension which is essentially flush withelongated slot 38 formed in cavity wall 22.

In FIGS. 4A and 4B, an alternative embodiment of the electro-cauterizingcannula assembly hereof is shown. This cannula assembly is similar tothe above-described cannula assembly in all respects except for theextension on actuation element 37. In this alternative embodiment, theextension on actuation 37′ is provided with a spring biased ball bearing48 that projects slightly beyond cannula cavity wall surface 22. Wheninner cannula base 10′ is pushed into cannula cavity 20 in the vicinityof actuation element 37′, ball bearing 48 engages within indentationring 49 circumferentially formed about inner cannula base 10′. Notably,spring biased ball bearing 48 functions as an engaging means for innercannula base 10′.

As shown in FIG. 4A, the engaging means for outer cannula base 17′ isalso realized as a spring biased ball bearing 50 installed throughcannula cavity wall 22. Outer cannula base 5′ is provided with anannular flange 47 and indentation ring 49 circumferentially formed aboutouter cannula base 17′. As shown, annular flange 57 establishes surfaceto surface contact with peripheral surface 58 area of the housing whencannula base 5′ is pushed into cannula cavity 20. In this position, ballbearing 50 engages within indentation ring 49 and a snap-fit engagementis established. This arrangement serves to retain both inner and outercannulas 4′ and 4 and cannula cavity 20′, in a releasable manner, asactuation element 37′ is caused to reciprocate periodically. The outercannula is simply removed from cannula cavity 20 by quickly pulling onouter cannula tube 5 with a modest degree of force, to overcome the biasforce of engaged ball bearing 50. Similarly, the inner cannula is simplyremoved by quickly pulling on inner cannula tube 4′ to overcome biasforce of engaged ball bearing 50. Advantageously, this cannula assemblyretention mechanism can also provide a safety release feature, in thatif inner cannula 4′, for example, becomes snagged during an operation,it will disengage from the reciprocation means 6 if a proper springbiasing force is selected for ball bearing 50.

FIGS. 7A, 7B and 8 also show an electro-cauterizing cannula assemblyaccording to the present invention which is adapted for use withliposuction instruments having cannula retention capabilities of thesnap-in type described above. Notably, the elements which correspond toinner and outer cannulas illustrated in FIGS. 2A through 3B1, areindicated by similar reference numbers.

In the embodiment featured in FIGS. 7A and 7B, inner cannula base 10″has a deeply formed spherical indentation 52 which is adapted to receiveball bearing 48 mounted in the extension of in actuation element 37. Tofacilitate guiding ball bearing 48 into spherical indentation 52, alongitudinally extending groove 53 is formed in inner cannula base 10″.Also, as shown, widened recess portions 53A and 53B are provided atopposite ends of groove 53 to facilitate initial insertion of ballbearing 48 in groove 53. When inner cannula base 10″ is slid intocannula cavity 20, ball bearing 48 snaps into indentation 52 toestablish a locked position. Biased ball bearing 48 engaged in sphericalindentation 52 serves to retain inner cannula 5 within cannula cavity20, while facilitating reciprocation of inner cannula 5 when actuationelement 37′ is caused to reciprocate.

Similar to the snap-fit inner cannula retention mechanism illustrated inFIGS. 7A and 7B, FIG. 8 shows outer cannula base 17″ having alongitudinally extending groove 55. Also, as shown, widened recessportions 55A and 55B are formed at opposite ends of groove 55 tofacilitate insertion of ball bearing 50 into spherical indentation 56.When outer cannula base 17″ is slid into cannula cavity 20, ball bearing50 snaps into spherical indentation 56 to establish a locked position.When this occurs, annular flange 57 will engage with outer peripheralsurface 58, about circular access opening leading into cannula cavity,shown in FIG. 4A. Upon such engagement, outer cannula 5 is renderedstationary relative to hand-holdable housing 2. As with inner cannula 4,the outer cannula is simply removed from cannula cavity 20 by pulling onouter cannula tube 5 with a modest degree of force to overcome the biasforce of engaged ball bearing 50.

In order to selectively adjust the amount of cannula excursion permittedduring a liposuction operation, piston-type motor 6 can be modified, asshown in FIG. 5, to produce a third embodiment of the liposuction deviceof the present invention. As illustrated in FIG. 5, the basic structureof liposuction device 1C is similar to that shown in FIGS. 1A through1C, except that a user-adjustable intermediate housing wall 88 isdisposed between the inner walls 31A of chamber housing 31 and the outerwalls 34A of movable piston 34. Intermediate housing wall 87 is operablyassociated with an excursion selection means realized as a slidablemember 88 fixedly attached to the upper portion of intermediate housingwall 59. Preferably, slidable member 88 extends through a slot 89 formedin the wall of housing 2 and can be slid, for example, by movement ofthe surgeon's thumb. The function of intermediate housing wall 87 is toeffectively raise the height of the chamber housing wall, and thusselectively increase distance d, defined, for example, as the distancebetween gas outlet port 32 in piston 34 and upper portion 63 of thechamber housing wall. In this way, movable piston 34 must undergo alarger displacement before compressed gas will be released and piston 34permitted to be forced downwardly under the biasing force of biasingspring element 40.

As illustrated in the embodiment shown in FIG. 5, it is also possible tocontrol the rate of reciprocation of the inner cannula by controllingthe rate of gas flow entering chamber 33 of piston-type motor 6. Thiscan be achieved using a conventional gas flow regulation device 78inserted between source of gas “S” and inlet port 32 of chamber housing31. As shown, tubing sections 79A and 79B are used to achieve fluidcommunication between these elements. Typically, cannula reciprocationrates will be in the range of 30 to 90 reciprocation cycles per minute,and the corresponding gas flow rates will depend on parametersincluding, for example, the compliance of biasing spring 40, the volumesof movable piston 34 and chamber housing 31, the cross-sectionaldiameter of gas inlet port 32, and the cross-sectional diameter of gasoutlet ports 36 in the piston.

Referring to FIGS. 6A through 6D, there is shown another embodiment ofthe liposuction device of the present invention. In liposuction device1F, the housing and cannula assembly are generally similar to those ofthe previously described embodiments, with the exception of severaldifferences which will be described below.

As illustrated in FIG. 6A, a pair of piston-type motors 6A and 6B of thetype generally indicated in FIGS. 1A through 1C and 5, are fixedlyinstalled within respective motor cavities 30A and 30B of housing 2.Each piston-type motor 6A and 6B has a respective chamber housing andmovable piston, indicated by 31A and 31B, and 34A and 34B, respectively.Actuation elements 37A and 37B are fixedly connected to respectivepistons 34A and 34B and project through respective elongated slots 38Aand 38B formed in cannula cavity wall 22; this is achieved in a mannersimilar to that described in connection with the embodiments shown inFIGS. 1A through 1C, 4A, 4B and 5. While not shown in FIG. 6A,preferably a rod or bar is fixedly attached between actuation elements37A and 37B in order to maintain them a fixed distance apart, and yetprovide an operable connection between the inner cannula 4′ andactuation elements 37A and 37B in the manner described below. As shownin FIG. 6B, this embodiment includes hinged cover panel 21 in a mannersimilar to that described in the embodiments of FIGS. 1A, 1C, 5, 6A and8A.

As illustrated in FIG. 6A, inner cannula base 10′″ has first and secondreceiving slots or notches 12A and 12B, into which extensions 13A and13B of respective actuation elements 37A and 37B are received. Suchoperable connections between movable pistons 6A and 6B and inner cannulabase 10′″ enables inner cannula 4′ to reciprocate relative to housing 2when actuation elements 37A and 37B are caused to reciprocate relativeto respective gas driven motors 6A and 6B.

In order to control the filling and venting of chambers 33A and 33B ofthe first and second piston motors, to effectuate cyclical reciprocatingmotion of actuation elements 37A and 37B and thus inner cannula 4′, amechanically-operated gas flow control device 90 is provided. As shownin FIG. 6A, gas flow control device 90 is employed in operableassociation with an external source of pressurized gas (not shown), gasinlet ports 32A and 32B, and movable pistons 34A and 34B.

As illustrated in greater detail in FIGS. 6C and 6D, gas flow controldevice 90 comprises a shuttle valve housing or casing 91, having firstand second shuttle chambers 92A and 92B. These shuttle chambers areseparated by a shuttle valve member 93 which is fixedly attached to aslidable shaft 94. As illustrated, shuttle valve member 93 is slidablebetween two positions or states “A” and “B”. In order to achieve thisshaft 94 extends through bores 95A and 95B formed in shuttle chamber endwalls 91A and 91B respectively, in which seals 96A and 96B are installedin a conventional manner. When the shuttle valve 93 is centrallydisposed in casing 91 between states A and B, shaft ends 94A and 94Bprotrude equally beyond respective bores 95A and 95B.

Adjacent one end of the cylindrical shuttle chamber side wall 98, afirst gas exit port 89A is formed, whereas adjacent the other end ofwall 98, a second gas exit port 98B is formed, as shown. At aboutintermediate the end walls, a gas inlet port 100 is formed in shuttlechamber side wall 98. A pair of annulus-shaped shuttle valve stops 101Aand 101B are formed at opposite end portions of the interior surface ofcylindrical wall 98. These stops 101A and 101B serve to limit slidingmovement of shuttle valve 93 when shaft 94 is displaced in one of twopossible axial directions by actuation elements 37A and 37B,respectively, as shown in FIG. 6A. As will be discussed in greaterdetail hereinafter, it is these actuation elements 37A and 37B whichdisplace shaft 94 and thus shuttle valve 93 between one of two states,as movable pistons 34A and 34B are caused to reciprocate. Preferably, atleast a portion of shuttle valve 93 is formed of a ferromagneticmaterial so that ferrous end walls 102A and 102B will attractferromagnetic shuttle valve 93 and pull it against one of stops 110A and101B and into gas flow state A or B, i.e., when shuttle valve 93 isbrought into proximity therewith upon displacement of shaft 94 by one ofactuation elements 37A and 37B. Peripheral side surfaces of shuttlevalve 93 are provided with seals 103 to prevent gas leakage betweenshuttle chambers 92A and 92B.

As illustrated in FIG. 6A, first gas exit port 99A of device 90 is influid communication with second chamber housing 31B by gas channel 104,whereas second gas exit port 99B is in fluid communication with firstchamber housing 31A by gas channel 105. In the illustrated embodiment,gas inlet aperture 106 is formed through housing 2 and permits gaschannel 107 to establish fluid communication between gas inlet port 100and the external source of pressurized gas. Notably, chamber housings31A and 31B, shuttle valve housing 91, gas channels 104, 105 and 107 canbe realized as discrete elements, as shown, or alternatively, asintegrally formed elements which are part of the interior of thehand-holdable housing itself.

The principal function of gas flow control device 90 is to control theflow of gas to pistons 34A and 34B so that only one of the gas pistonsis actively driven at a time, while the other is passively driven. Themanner of operation of gas flow control device 90 in cooperation withthe periodic displacement of pistons 34A and 34B, will now be described.

Owing to the fact that shuttle valve 93 is magnetically biased to be inessentially one of two possible positions, or gas flow states, gas willinitially be caused to flow into one of piston-chamber housings 31A or31B, and cause its respective piston and actuation element to move away(i.e., protract) from its respective chamber housing. Only along a smallportion of the piston excursion will shuttle.valve shaft 94 and thusshuttle valve 93, be displaced within shuttle valve housing 91 as theactively driven piston is displaced upon buildup of pressurized gaswithin its respective chamber.

To illustrate this cyclical process, it will be assumed that gas flowcontrol valve 90 is initially in state A, as shown in FIG. 6A. Here,piston 34A has reached its maximal displacement and pressurized gaswithin chamber 33A has been substantially vented through gas outlet port26A and through ports 39A and 39B. In this position (state A), shuttlevalve 90 is magnetically biased against stops 101B so that gas is causedto flow from the external gas source (not shown), through first shuttlechamber 92A and into second chamber housing 33B. With shuttle valve 93in this state, gas pressure is allowed to build up in chamber 33B,displacing piston 34B and actuation element 37B to protract from secondchamber housing 31B. Therewhile, inner cannula base 10′″ is caused toundergo an outwardly directed excursion within cannula cavity 20,commensurate with the active displacement of piston 34B. During pistonexcursion (i.e., travel) defined over length L₁, shuttle valve 93remains in stage A against stop 101B.

Then over piston excursion L₂, actuation element 37B contacts shaft end94B and displaces shuttle valve 93 away from stop 101B to aboutmid-position in shuttle housing 91, approximately over input port 100,at which point, magnetic shuttle valve 93 is pulled toward ferrous plate102A into state B and against stop 101A, as shown in FIG. 6A withphantom lines. At this phase in the cycle, piston 34A is fully retractedwithin chamber housing 31A, while piston 34B is fully protracted fromchamber housing 31B and displaced a distance L₃ from the upper portionthereof (i.e., L₃=L₁+L₂). In State B, gas flow control device 90 directsthe flow of pressurized gas from the external source, along channel 107,through second shuttle chamber 92B and along channel 105 and into pistonchamber housing 31A.

Magnetically biased shuttle valve 93 remains in state B as chamberhousing 31A fills with pressurized gas, expanding the chamber 33A andactively displacing piston 34A away from chamber housing 31A, whilecausing piston 34B to passively retract back into its chamber housing31B. All the while, inner cannula base 10′″, being operably associatedwith actuation elements 37A and 37B, undergoes a commensurate amount ofinwardly directed excursion within cannula cavity 20. When piston 34B isdisplaced an amount of distance L₄, actuation element 37A contacts shaftend 94A and displaces shuttle valve 93 a small distance L5, at whichpoint, magnetic shuttle valve 93 is pulled towards ferrous plate 102B,back into state A and against stop 101B. At this phase in the cycle,piston 34B is fully retracted within chamber housing 31 while piston 34Ais fully protracted within chamber housing 31A and displaced at adistance L₆ from the upper portion thereof (i.e., L₆=L₄+L₅). In state A,gas flow control device 90 directs the flow of pressurized gas from theexternal source, along channel 107, through first shuttle chamber 92A,along channel 104 and into piston chamber housing 31B.

Magnetically biased shuttle valve 93 remains in state A as chamberhousing 91B fills with pressurized gas, expanding chamber 3B andactively displacing piston 34B away from chamber housing 31B, whilecausing piston 34A to passively retract back into its piston chamberhousing 31A. All the while, inner cannula base 10′″, being operablyassociated with actuation elements 37A and 37B, undergoes once again acommensurate amount of outwardly directed excursion within cannulacavity 20. With a preselected gas pressure and flow rate set at gasinlet port 100 of device 90, the above-described process of gas filling,venting and flow control occurs automatically at a corresponding rate,resulting in periodic reciprocation of inner cannula 10′″ relative tohand-holdable housing 2. In turn, this periodic reciprocation of innercannula 4′ results in periodic displacement of the general location ofaspiration occurring along the length of the cannula assembly.

Referring to FIGS. 9A through 9F, there is illustrated yet a seventhembodiment of the liposuction device of the present invention. Ingeneral, liposuction device 1G has a pistol-shaped housing 110 whichcomprises a barrel portion 111 and a detachable handle portion 112.Instead of using a reciprocating piston motor to translate inner cannula4′ relative to housing 100, this embodiment utilizes a rotary-type motor113. In operative association with a cam mechanism, generally indicatedby reference numeral 114, rotary-type motor 113 causes actuation element115 to cyclically slide back and forth and cause inner cannula 4′ toperiodically reciprocate relative to barrel portion 111 of thepistol-shaping housing.

As illustrated in FIGS. 9B through 9D, barrel portion 111 of the housingcomprises a cannula cavity 116 adapted for slidably receivingcylindrically-shaped base 17 of inner cannula 4′, in a manner describedhereinabove. Cannula cavity 116 is also provided with a longitudinallyextending access opening, over which a hingedly connected cover panel117 is provided. As illustrated in FIG. 9E, cover panel 117 facilitatesinsertion of the cannula assembly into, and removal of the cannulaassembly from, cannula cavity 116 in a manner similar to that describedin connection with liposuction instrument 1A of FIGS. 1A through 1C, inparticular. As illustrated in FIG. 9C in greater detail, inner cannulabase 10 is adapted to be received within cannula cavity 116 and outercannula base flange 19 releasably received with annular recess 118formed in cannula cavity wall 22.

To install inner cannula 4′ into cannula cavity 116, semi-flexibletransparent tubing 15 is connected to inner cannula outlet port 11. Thencover panel 117 is opened and tubing 15 is fed out through rear port 119of the barrel portion, as illustrated in FIGS. 9C and 9F. Inner cannulabase 10 is then slid into cavity 116 with an extensional portion ofactuation element 115 received in notch 12. Then outer cannula 5′ isslid over the distal end of inner cannula 4′ until outer cannula base 17is received within annular recess 118. Thereafter, as shown in FIG. 9E,cover panel 117 is snapped closed using, for example, a spring biasedlocking device 120 of the type previously described above. Removal ofinner and outer cannulas simply involves a reversal of the aboveprocedure.

Alternatively, using spring biased actuation elements and inner andouter cannulas of the type shown in FIGS. 4A and 4B, barrel portion 11can be realized without necessity of hinged cover panel 117. In such analternative embodiment, the inner and outer cannulas can be snap-fittedinto and pulled out of cannula cavity 116 in a manner similar to thatdescribed hereinabove.

As illustrated in FIGS. 9B through 9F, barrel portion 111 houses cammechanism 114 which is operably associated with (i) rotary motor 113contained within the handle portion, and (ii) actuation element 115which slidably passes through a longitudinal slot 121 formed within theupper wall of cannula cavity 116. As in the other previously describedembodiments, actuation element 115 includes extension 115A that passesthrough elongated slot 121 and is received within notch 12 formed ininner cannula base 10. In addition, cam mechanism 114 of the illustratedembodiment inherently embodies gear reduction. In this way, a highangular shaft velocity of rotary motor 113, can be efficientlytransformed into reciprocational strokes of the cannula, occurring at asubstantially lower rate. With such an arrangement, as rotary motor 113is caused to rotate under either gas pressure or electrical power,actuation element 115 is caused to reciprocate within elongated slot 121by way of cam mechanism 114, and thereby cause inner cannula 4′ toperiodically reciprocate relative to housing 110. This motion results inperiodic displacement of the general location of aspiration occurringalong the length of the cannula assembly.

As illustrated in FIGS. 9B and 9C, cam mechanism 114 of the preferredembodiment comprises a drive wheel 122 having a first predeterminednumber of gear teeth 123 disposed thereabout. Drive wheel 122 isrotatably mounted to a shaft 124 mounted through an opening in the toppanel of an accommodating section 125 of the barrel portion. Cammechanism 114 also includes a connective element 126 having first andsecond ends 126A and 126B, respectively. First end 126A of theconnective element in pivotally attached to the drive wheel 122 at apoint posed away from the axial center 124, whereas second end 126B ispivotally connected to actuation element 115 as shown. In order toadjust the distance away from the axis of rotation 124 at which thefirst end of the connective element is pivotally attached, a radiallyformed slot 127 is formed in drive wheel 122. A plurality of widenedcircular apertures 128 are disposed along radial slot 127, as shown inFIGS. 9B and 9D. In this way, a spring-loaded cylindrical pin 129passing through the first end of connective element 126, can beselectively locked into one of apertures 128 by pulling upwardly uponpin 129 and setting its cylindrical base 129A into the desired aperture128. In FIG. 9D, pin 129 is shown to further include pin head 129B, ahollow bore 129B, and an axle 129D having heads 129E and 129F. As shown,a spring 129G is enclosed within bore 129C, about axle 129D and betweenhead 129F and an inner flange 129H. By selectively locking the first end126A of connective element 126 into a particular circular notch 128using spring loaded pin 129, the distance of the first end of theconnective element from axial center 124 can be set, and thus the amountof inner cannula excursion (and effective aspiration aperturedisplacement) thereby selected. To permit access to spring-loaded pin129, the top panel of accommodating portion 125 of the housing isprovided with hinged door 132 that can be opened and snapped closed asdesired.

As illustrated in FIGS. 9B and 9C, handle portion 112 of the housingencloses a substantial portion of rotary motor 113 whose shaft 133projects beyond the handle portion and bears a gear wheel 134. As shown,gear wheel 134 has a second predetermined number of gear teeth 134Adisposed circumferentially thereabout, which mesh with drive wheel teeth123. Notably, to permit the rear portion 19 of cannula cavity 16 toextend all the way towards the rear of the barrel portion for passageand exit of aspiration hose 15, shaft 133 of the motor is mounted offcenter of handle portion 113, as shown in FIGS. 9C and 9F.

Rotary motor 113 is preferably an electric motor whose shaft speed iscontrollable by the voltage applied to its terminals. Such speed controlcan be realized by a conventional speed control circuit 135 connectedbetween motor 113 and a conventional 110-115 volt, 50-60 Hertz powersupply. As illustrated in FIG. 9C, conventional electrical cord 136 andon/off power switch 150 can be used to connect control circuit 135 andthe power supply. Control over the output voltage produced from speedcontrol circuit 115 and provided to electrical motor 113, can beadjusted, for example, by changing the resistance of a potentiometer 137which is operably connected to the speed control circuit. As shown inFIG. 6C in particular, this potentiometer 137 can be embodied within atrigger mechanism 138 which is connected, for example, to handle portion112 of the housing 110. By pulling trigger 38, the speed of rotary motor113 can be controlled, and consequently, so too the rate ofreciprocation of inner cannula 4′ relative to outer cannula 5′, and thusthe rate of displacement of the effective aspiration apertures.

To connect handle portion 112 to barrel portion 111 and permitdisconnection therebetween for cleaning, sterilization and generalservice, handle portion 112 is provided with flange 140 and thumboperable spring element 141. Barrel portion 111, on the other hand, isprovided with slot 142, catch 143, and cavity 144. To connect handleportion 112 to barrel portion 111, shaft 133 is vertically passedthrough channels 144 and 145 until gear 134 is slightly below the planeof drive wheel 122. Then, spring element 141 is inserted within cavity144 while flange 140 is guided into slot 142. By pushing the rearportion of handle 112 in the longitudinal direction of cannula cavity116, spring element 141 will snap over and clasp catch 143 as shown inFIG. 12C. In this configuration, handle portion 112 is secured to barrelportion 111 and gear teeth 123 will mesh with drive wheel teeth 134A. Todisconnect handle portion 112 from barrel portion 11, the surgeon'sthumb simply depresses spring-element 141 downwardly and then, by movinghandle portion 112 slightly rearwardly, then downwardly, flange 140 isdislodged from slot 142 and motor shaft 133 can be withdrawn fromchannels 144 and 145. In this disassembled state, handle portion 110 andbarrel portion 112 can be individually cleaned and sterilized usingconventional procedures known in the state of surgical instrument art.

Liposuction device 1G described above employs an electrical rotary motorto effectuate reciprocation of inner cannula 4′ relative to housing 110.However, in an alternative embodiment, it is possible to effectreciprocation of the outer cannula while the inner cannula is stationarywith respect to the housing, as shown in FIGS. 6A through 7. Also, it ispossible to employ a conventional gas driven rotary motor in lieu ofelectric rotary motor 113. In such an embodiment, trigger 138 can beoperatively associated with a gas flow control valve. Thus, bycontrolling the rate of gas flow to the gas rotary motor upon actuationof trigger 138, the angular velocity of shaft 133 can be controlled andthus the rate of reciprocation of inner cannula 4′ relative to housing110.

Having described various illustrated embodiments, it is appropriate atthis juncture to describe the method of the present invention using, forpurposes of illustration only, the liposuction instrument 1C illustratedin FIG. 5.

In general, the surgeon prepares in a conventional manner, the area ofskin below which liposuction is to be performed. Typically, this entailsmarking various zones where radial displacement of the aspirationapertures is to occur. Liposuction instrument 1C of the presentinvention is assembled as described above so that aspiration apertures8A′, 8B′ and 8C′ of cannula assembly 3′ are in communication with avacuum source (not shown). A small incision is then made in thepatient's skin in a conventional manner, and the distal portion of thecannula assembly is inserted into a premarked radial zone. Aspressurized gas is provided to piston motor 6, inner cannula 10 willautomatically reciprocate causing the general location of the suctionapertures to be automatically displaced along each tunnel of fattytissue. During the operation of the instrument, the surgeon's handholding the liposuction instrument is maintained essentially stationarywith respect to the patient. Fatty tissue is aspirated through theperiodically displaced aspiration apertures, and transferred into areservoir tank operably associated with the vacuum source.

As deemed necessary, the surgeon can selectively increase the rate ofaspiration aperture travel along the distal end of the cannula assembly.This can be achieved by a foot-operated gas flow control device 78 whichcontrols the rate of gas flow to piston motor 6. Also, the amount ofinner cannula excursion (i.e., aspiration aperture travel) can also beselected by adjusting the compliance of spring 40 through rotation ofthreaded element 42.

In the illustrative embodiments described hereinabove, the outer cannulahas been made from an electrically non-conductive material (i.e.,achieving electrical isolation between the cauterizing electrodessupported on the outer cannula, and electrically conductive innercannula). The inner cannula has been made from stainless steel, offeringthe advantage of being easily cleaned and sterilizable. The plasticouter cannula offers the advantage of electrical insulation, lowmanufacturing cost and disposability. Preferably, when making the outercannula from a suitable plastic material, injection molding processescan be used.

In FIG. 10, an alternative embodiment of the liposuction instrument ofFIG. 9 is shown. While this embodiment of liposuction instrument hereof180 is similar to the embodiment shown in FIG. 9, there are a number ofdifferences. For example, an actuator 181 magnetically-coupled to an airpowered cylinder 182 is used to reciprocate the base portion 10 of theinner cannula of its electro-cauterizing cannula assembly. Themagnetically-coupled air powered cylinder and actuator subassembly (182,181) can be realized as Model No. MG 038 commercially available fromTol-O-Matic, Inc. of Hamel, Minn. As shown in FIG. 10, the ends of theair powered cylinder 182 are supported by an external guide and supportsystem comprises brackets 183A and 183B, which are integrated withinterior portions of the hand-holdable housing. The actuator block 181,which is mounted about the cylindrical shaft of the cylinder 182, isreciprocated between the support brackets 183A and 183B in response topressurized air (gas) flowing into its first air input/output port 184A,and then the second air input/output port 184B, repeatedly in analternating manner, causing the actuator 181 to reciprocate along thecylinder 182. Such pressurized air streams are provided by an air-flowcontrol device 185.

As shown in FIG. 10A, the air flow control device 185 has one air supplyport 185A, first and second air output/return ports 185B and 185C, andfirst and second air exhaust ports 185D and 185E. Air supply port 185Ais supplied with pressurized air through tubing 185A1 connected to flowrate control unit 219 which is controlled by electrical signals producedby trigger 138 when pulled to a particular degree of angular function ofdeflection. The control unit 219 is to control the flow of air fromsupply tubing section 219A connected to an external source ofpressurized air. The first and second air output/return ports 185B and185C, are arranged in fluid communication with the first and second airinput/output ports 184A and 184B of the cylinder 182, respectively, byway of air tubing sections 186 and 187.

As shown in FIG. 10A, air-flow control device 185 has an air flowcontrol shaft 188 with air flow directing surfaces 188A. Air flowcontrol shaft 188 is slidably supported within the housing of thedevice. The function of the flow control shaft is to commute air flowbetween its various ports described above in response to the position ofthe actuator 181 along the cylinder 182 during device operation. Inorder to achieve such functions, the air-flow control shaft 188 of theillustrative embodiment is mechanically coupled to an actuator strokecontrol rod 189 by way of a mechanical linkage 190. Linkage 190 issupported by brackets 191A, 191B and 191C and secured to the interior ofthe hand-holdable housing. Along the actuator stroke control rod 189, apair of actuator stops 192A and 192B are disposed. In the illustrativeembodiment, stops 192A and 192B are disposed. In the illustrativeembodiment, stops 192A and 192B are realized as slidable rods which areadapted to lock into different detented positions along the strokecontrol rod 189 when the surgeon presses the top thereof (locatedoutside of the housing) downwardly and then in the direction of theadjustment, releasing the control stop at its desired location. In someembodiments, it may be desirable to fix one of the control stops whileallowing the other control stop to be adjustable along a selectedportion of the length of the stroke control road 189. In alternativeembodiments, actuator stroke control can be realized using other typesof adjustment mechanisms including, for example, an externallyaccessible adjustment screw mechanism, in which adjustment (rotation) ofa single knob or thumb0wheel enables the surgeon to set the strokelength of the inner cannula and thus the aspiration aperture thereof;electronic control mechanisms, in which actuation of an electronic orelectrical device, such as foot pad or electrical switch enables thesurgeon to translate the position of one or both of the stroke controlstops by electro-mechanical means (including linear motors, gearedrotary motors and the like).

As shown in FIG. 10A, the air flow control shaft 188 has two primarypositions; a first position, in which pressurized air from the airsupply port 185A is directed to flow through the second airoutput/return port 188C of the air flow control device, along tubing 187and into the second input/output port 184B of the cylinder 182, whilethe second input/outlet port 184B of the cylinder is in communicationwith the first exhaust port 185D of the air flow control device 185causing inner cannula to project away from the housing; and a secondposition, in which pressurized air from the air supply port 185A isdirected to flow through the first air output/return port 188B of theair flow control device, along tubing 186 and into the firstinput/output port 184A of the cylinder, while the second input/outletport 184B of the cylinder is in communication with the second exhaustport 185E of the air flow control device 185, causing the inner cannulato retract inwards towards the housing. By virtue of this arrangement,the actuator 181 is automatically driven back and forth between strokecontrol stops 192A and 192B along the cylinder stroke rod in response topressurized air flow into the air flow control device 185. When theelectro-cauterizing cannula assembly of FIG. 11A is installed within thecannula cavity of the liposuction device, as described hereinabove, theinner cannula 4 will be caused to reciprocate relative to the outercannula 5. In the illustrative embodiment, the length of the excursionof the inner cannula 4 is determined by the physical spacing betweenmechanical stops 192A and 192B. By varying the spacing of these stopsalong the stroke control rod 182, the maximum excursion of the innercannula relative to the stationary outer cannula can be simply andeasily set and reset as necessary by the surgeon.

In FIG. 11A, an electro-cauterizing cannula assembly 3″ is shown for usewith the liposuction instrument of FIG. 10. In this illustrativeembodiment, both the inner and outer cannulas are made of anelectrically non-conductive material such as sterilizable plastic. Inthe embodiment of FIG. 10, hand-holdable housing is preferably made froman electrically non-conductive material. Electrically conductiveelectrodes 195A, 195B, 195C an 195D are inserted within the inneraspiration apertures 8A, 8B, 8C and 8D, and electrical wiring 196 runsto the inner cannula base portion 10, wherein an electrical contact pad197 is embedded. Electrically conductive electrodes 160A, 160B, 160C and160D are also inserted within the outer aspiration apertures 16A, 16B,16C and 16D, and electrical wiring 168 runs to the outer cannula baseportion 19, wherein an electrical contact pad 166B is embedded. Anelectrical contact pad 176B is also embedded within the base portionrecess within the hand-holdable housing.

As shown in FIGS. 10 and 11, an electrical contact rail 198 is embeddedwithin the side wall surface of the cannula cavity so that electricalcontact pad 197 on base portion 10 of the inner cannula establisheselectrical contact therewith to apply RF (supply/return) power signalsto the electrodes in the inner cannula during liposuction operations. Insuch circumstances, two sets of electrical connections occur. Firstly,the base portion 10 of the inner cannula is securely engaged by theactuator block 181 (snap-fitting or other suitable means) and theelectrical contact pad 197 contact with the electrical rail 198 embeddedwithin the inner side wall surface of the cannula cavity. Secondly, thebase portion 19 of the outer cannula is received within the base portionrecess of the hand-holdable housing and the electrical contact pad(i.e., RF power supply terminal) 176B embedded therewithin establishescontact with the electrical contact 166B embedded within the, baseportion of the outer cannula. By virtue of these electrical connections,RF supply potentials are applied to the electrode portions of the innercannula, while RF return potentials are applied to the electrodeportions of the outer cannula, whereby electro-cauterization occurs.

In FIGS. 13A through 13D, an alternative electro-cauterizing cannulaassembly 3′″ is shown for use with the liposuction instrument shown inFIGS. 10 and 10A, and readily adaptable for use with other liposuctioninstruments of the present invention. In this particular illustrativeembodiment, both the inner and outer cannulas are made of anelectrically conductive material. The hand-holdable housing is made froman electrically non-conductive material (e.g. plastic). Between these,electrically non-conductive cannulas 4 and 5 means are provided formaintaining electrical isolation between the electrically conductivecarrier and outer cannula which, during electro-cauterization, aremaintained at an electrical potential difference (i.e., voltage) of 800volts or more. In general, a variety of different techniques can beemployed for carrying out this function. For example, a thin coating ofTeflon™ material 200 can be applied to the outer surface of the innercannula, and/or to the inner surface of the outer cannula Alternatively,a series of electrically-insulating spacer/washers made from Teflon®ceramic, or like material can be mounted within circumferentiallyextending grooves formed periodically about the inner cannula tomaintain sufficient spacing and thus electrical insulation between theinner and outer cannulas. Preferably, the spacing between each pair ofinsulating spacers is smaller than the length of the bore 18 formed inthe electrically conductive base portion of the outer cannula, asillustrated in FIG. 13A.

As shown in FIG. 11G, electrical contact rail (i.e. RF power supplyterminal) 198 embedded within the cannula cavity establishes electricalcontact with the base portion 10 of the inner cannula when the cannulaassembly is installed in the housing of the device. Also, electricalcontact pad 176B embedded within the recess portion of the housingestablishes electrical contact with the base portion of the outercannula when the cannula assembly is installed within the hand-holdablehousing. In the assembled state, two sets of electrical connectionsoccur. First, the electrically conductive base portion of the innercannula is engaged by the electrical contact rail 198. Second, the baseportion of the outer cannula is received within the base portion recessand the base portion of the outer cannula establishes contact with theelectrical contact 176B embedded within the recess portion. By virtue ofthese electrical connections, RF supply potentials are applied to theinner cannula, while RF return potentials are applied to the outercannula. The potential difference(s) between these surfaces about theaspiration apertures enable electro-cauterization of tissue as it isbeing aspirated through the aspiration aperture moving along the cannulaassembly.

In another illustrative embodiment of the present invention, the innercannula 4 is made of an electrically non-conductive material such asplastic. The outer cannula is made of electrically conductive material(e.g., stainless steel). The hand-holdable housing is made from anelectrically non-conductive material (e.g., plastic). Electricallyconductive electrodes are inserted within the inner aspiration aperturesthereof, and electrical wiring run to the inner cannula base portion,wherein an electrical contact rail is also embedded.

As shown in FIG. 14G, an electrical contact rail 213A is also embeddedwithin the side wall of the cannula cavity. An electrical contact padembedded within the recess of the plastic hand-holdable housingestablishes electrical contact with the base portion of the electricallyconductive outer cannula. Thus, when the cannula assembly is installedwithin the hand-holdable housing, two sets of electrical connectionsoccur. First, the base portion of the inner cannula is engaged by theactuation means and the electrical contact pad therewithin establishescontact with the electrical contacts embedded within the base portion ofthe inner cannula. Secondly, the base portion of the outer cannula isreceived within the base portion recess and the electrical contact padsembedded therewithin establish contact with the electrical contactembedded within the base portion of the outer cannula. By virtue ofthese electrical connections, RF supply potentials are applied to theelectrode portions of the inner cannula, while RF return potentials areapplied to the electrode portions of the outer cannula.

In yet other alternative embodiments of the present invention,hemostasis can be carried out in the powered liposuction instrumentshereof by producing ultrasonic energy (having a frequency of about 50kilohertz) and delivering the same to the aspiration aperture regions ofthe cannula assembly during liposuction procedures. Such ultrasonicenergy will cause protein coagulation of aspirated tissue in the regionsof the aspiration apertures. When the frequency of the ultrasonic energyis reduced to about 20-25 kilohertz, liquefaction or lipolysis of theaspirated tissue will occur. Such modes of operation can be added to anyof the electro-cauterizing liposuction instruments of the presentinvention, or to liposuction instruments with electro-cauterizingcapabilities.

In FIGS. 14 through 14C, a preferred embodiment of the ultrasoniccauterizing liposuction instruments of the present invention is shown.In general, the embodiment shown in FIGS. 14 through 14C is similar tothe liposuction instrument of FIG. 10, except that it includes severaladditional means which enable it to effect protein coagulation (and thushemostasis) during liposuction using ultrasonic energy having afrequency of about 50 kilohertz and sufficient power. As shown, a set ofpiezo-electric crystals 210 are embedded about the lumen of the innercannula and encased within the base portion of the inner cannula made ofplastic.

As shown in FIG. 1, an electrical signal generator 216 external to theliposuction device is provided for supplying electrical drive signals toterminals 214 via control circuit 215 when it is enabled by manualactuation of trigger 138. The electrical signal generator 216 should becapable of producing electrical signals having a frequency in the rangeof about 15 to 60 KHz, at a sufficient power level. Any commerciallyavailable signal generator, used in medical applications, can be used torealize this system component. The electrical signals produced fromgenerator 216 are applied to the terminals of the piezo-electrictransducers embedded within the electrically non-conductive base portionof the inner cannula.

When the generator 216 is switched to produce signals in a rangecentered about 20 KHz, these signals are delivered to the array ofpiezo-electric transducers embedded within the base portion of the innercannula. These drive signals cause the piezo-electric transducers toproduce ultrasonic signals in substantially the same frequency range topropagate along the surface of the inner cannula and out the inner andouter aspiration apertures, enabling lipolysis or liquefaction ofaspirated fat tissue.

When the generator is switched to produce signals in a range centeredabout 50 KHz, these signals are delivered to the array of piezo-electrictransducers embedded within the base portion of the inner cannula. Thesedrive signals cause the piezo-electric transducers to produce ultrasonicsignals in substantially the same frequency range to establish standingwaves within the inner cannula which propagate out the apertures ofinner and outer cannula, enabling coagulation of protein moleculeswithin aspirated tissue, thus achieve hemostasis.

While carrying out lipolysis using ultrasonic energy producing meanswithin the liposuction device hereof, the surgeon may also desire toconduct hemostasis by coagulating protein molecules within tissue beingaspirated. As shown in FIG. 14, by pulling trigger 138, control circuit217 automatically commutes RF supply and return signals from the RFsignal supply unit 175 to power supply terminals 218 which, in turn, areconnected to contact pads 176A and 176B embedded within recess 17A,supporting the base portion of the outer cannula with respect to thehand-holdable housing.

As shown in FIGS. 10 and 14, a flow control switch 219 is providedwithin the handle of the housing in order to enable the flow ofpressurized air from air supply to the reciprocation means (e.g.,cylinder 182, etc.) only when manually actuated trigger 138 is manuallyactuated (or a foot pedal is depressed). When the trigger 138 is pulled,an electrical signal is sent to the flow control switch 219 which, inturn, permits a selected amount of pressurized air to flow into thereciprocation device (e.g., cylinder 182). The trigger switch 138 canhave a number of positions, at which different electrical signals areproduced for enabling flow control switch 219 to allow pressured air toflow to the reciprocation means 182 at different flow rates. This can beused to control the rate of reciprocation of the inner cannula relativeto the outer cannula, providing the surgeon with additional control overthe tissue aspiration process.

Notably, an improved degree of surgical control and user safety areprovided by the liposuction instrument of the present inventiondescribed above.

In particular, control circuit 217 prevents the liposuction instrumenthereof from carrying out cauterization along the length of its cannulaassembly, unless the cannula is reciprocating and/or aspirating. Thiscondition is detected when the trigger 138 is pulled to a particulardegree of angular deflection. The reason for providing such control overthe electro-cauterization functionality of the liposuction device hereofis to prevent inadvertent burning of tissue during liposuction and likeprocedures.

The function of the control logic circuit 215 is to enable thecommutation of 20-25 kilohertz electrical signals between the generator216 and the power supply rails 213A and 213B (to energize thepiezo-electric transducers 210 in the base portion of the inner cannula)only when aspirated tissue is flowing through the inner cannula. Thiscondition is detected when the trigger 138 is pulled to a particulardegree of angular deflection.

The electro-cauterization electrodes of the liposuction devices hereofcan be controlled in a variety of different ways. One way would be tocontinuously enable RF-based electro-cauterization during sensed tissueaspiration. In such “continuously-enabled” embodiments of the presentinvention, there will typically be no need for external switches toactivate the electro-cauterizing electrodes embodied within the cannulaassembly of the present invention.

Another way would be to enable RF-based electro-cauterization by way ofswitching RF supply and return signals to the electrodes during sensedtissue aspiration and the supply of an activation signal by the surgeon.Generation of the activation signal can be realized by manuallyactuating a second trigger, or pushing a button, or depressing a footpedal, external to the hand-supportable housing, or by automaticallydetecting a particular condition along the aspiration channel of thedevice or elsewhere therein.

While the liposuction instruments described above have been shown toinclude four symmetrically arranged aspiration apertures, it may bedesired in particular applications to provide a cannula assembly havinginner and outer cannulas with one, two or three aspiration apertures,rather than four as shown in the illustrative embodiments.

In some applications it may be desired to provide a cannula assemblyhaving a pair of diametrically opposed aspiration apertures, and anouter cannula with a single aspiration aperture. The outer cannulaassembly can be adapted to be rotatable in one of two angular positionsabout the inner cannula. In the first position, the single aspirationaperture formed in the outer cannula is aligned in registration with thefirst aspiration aperture along the inner cannula. When rotated into itssecond angular position, the single aspiration aperture of the outercannula is aligned in registration with the second aspiration aperturealong the inner cannula. The surgeon can easily switch the outer cannulabetween its first and second angular positions by rotating a smallradially extending projection, adjacent to the hand-holdable housing, ineither a clockwise or counter-clockwise direction to align theaspiration aperture on the outer cannula in registration with theselected aspiration aperture on the inner cannula. This feature of thepresent invention provides the surgeon with the option of changing whichside of the distal end of the cannula assembly is enabled to aspiratetissue during a liposuction procedure without the necessity of removing,repositioning and reinserting the cannula assembly within the housing.This technical feature can be used in conjunction with bothelectro-cauterizing as well as ultrasonic cauterizing functionalities ofthe present invention described above. When this aspiration apertureorientation control feature is provided in a liposuction instrument ofthe present invention having cauterizing electrodes embedded about theaspiration aperture(s) of a plastic outer cannula, an electricalcommunication mechanism can be embodied within the outer cannula in theproximal portion thereof and in its base portion, so that electricalconnectivity can be achieved between the cauterizing electrode on theouter cannula and its electrically conductive contact pad embeddedwithin the base portion of the outer cannula.

While the particular embodiments shown and described above have provento be useful in many applications in the liposuction art, furthermodifications of the present invention herein disclosed will occur topersons skilled in the art to which the present invention pertains. Allsuch modifications are deemed to be within the scope and spirit of thepresent invention defined by the appended claims.

What is claimed is:
 1. A powered tissue aspiration device comprising: ahand-holdable housing provided with a reciprocation means reciprocatablewithin said hand-holdable housing and a pair of power supply terminalsfor supplying a radio-frequency (RF) power signal to anelectro-cauterizing cannula assembly during tissue aspirationoperations, said electro-cauterizing cannula assembly being operablyconnectable to said hand-holdable housing and including a hollow innercannula having a distal end and a proximal end and an inner suctionaperture about'said inner cannula distal end, said inner cannulaproximal end further including an outlet port and a continuouspassageway which communicates said inner suction aperture with saidoutlet port, a hollow outer cannula having a distal end and a proximalend and an outer suction aperture about said outer cannula distal end,said hollow inner cannula being disposed within at least a portion ofsaid hollow outer cannula while permitting aspiration of tissue throughsaid outer and inner suction apertures, along said continuous passagewayand out of said outlet port, said hollow inner cannula being operablyassociatable with said reciprocation means, and said hollow outercannula being essentially stationary with respect to said hand-holdablehousing during device operation, so as to effectuate relative slidingmovement between said hollow inner and outer cannulas when saidreciprocation means reciprocates, so that the location of saidaspiration through said outer.and inner suction apertures isperiodically displaced along the length of said electro-cauterizingcannula assembly, and electro-cauterizing means associated with saidhollow inner and outer cannulas, for conducting said RF power signalalong at least a portion of said hollow inner and outer cannulas andeffecting coagulation of protein molecules within the tissue beingaspirated through said outer and inner suction apertures, wherein saidhollow outer cannula is electrically non-conductive and saidelectro-cauterizing means includes a cauterizing electrode providedabout said hollow outer suction aperture; and wherein said hollow innercannula is electrically conductive and the outer cannula base of saidhollow inner cannula includes electrical means for conducting said RFpower signal from a first one of said power supply terminals provided insaid powered tissue aspiration device to said hollow inner cannula. 2.The powered tissue aspiration device of claim 1, wherein said hollowouter cannula further comprises an outer cannula base extending fromsaid outer cannula proximal end and being adapted for releasablyconnecting with said hand-holdable housing, wherein said hollow innercannula further comprises an inner cannula base which is operablyassociatable with said reciprocation means by way of an actuation meansdisposed in said hand-holdable housing and reciprocatable by saidreciprocation means, and wherein said hollow inner cannula base furtherincludes said outlet port and said continuous passageway.
 3. The poweredtissue aspiration device of claim 2, wherein said electrical meanscomprises a device inserted within the outer cannula base of said hollowouter cannula and having an electrical contact element for conductingsaid RF power signal from said power supply terminals to said innercannula while said hollow inner cannula is being reciprocated withinsaid hollow outer cannula.
 4. The powered tissue aspiration device ofclaim 2, wherein the outer cannula base of said hollow outer cannulaincludes an electrical contact element for establishing electricalcontact with one of said power supply terminals within said poweredtissue aspiration device.
 5. The powered tissue aspiration device ofclaim 1, wherein said tissue aspiration operations include liposuction.6. A powered tissue aspiration device comprising: a hand-holdablehousing provided with a reciprocation means reciprocatable within saidhand-holdable housing and a pair of power supply terminals for supplyinga radio-frequency (RF) power signal to an electro-cauterizing cannulaassembly during tissue aspiration operations, said electro-cauterizingcannula assembly being operably connectable to said hand-holdablehousing and including a hollow inner cannula having a distal end and aproximal end and an inner suction aperture about said inner cannuladistal end, said inner cannula proximal end further including an outletport and a continuous passageway which communicates said inner suctionaperture with said outlet port, a hollow outer cannula having a distalend and a proximal end and an outer suction aperture about said outercannula distal end, said hollow inner cannula being disposed within atleast a portion of said hollow outer cannula while permitting aspirationof tissue through said outer and inner suction apertures, along saidcontinuous passageway and out of said outlet port, said hollow innercannula being operably associatable with said reciprocation means, andsaid hollow outer cannula being essentially stationary with respect tosaid hand-holdable housing during device operation, so as to effectuaterelative sliding movement between said hollow inner and outer cannulaswhen said reciprocation means reciprocates, so that the location of saidaspiration through said outer and inner suction apertures isperiodically displaced along the length of said electro-cauterizingcannula assembly, and electro-cauterizing means associated with saidhollow inner and outer cannulas, for conducting said RF power signalalong at least a portion of said hollow inner and outer cannulas andeffecting coagulation of protein molecules within the tissue beingaspirated through said outer and inner suction apertures, wherein saidhollow inner cannula is electrically non-conductive and saidelectro-cauterizing means includes a cauterizing electrode providedabout said inner suction aperture and said hollow inner cannula includesan electrical connection element for electrically connecting saidcauterizing electrode with a first one of said pair of power supplyterminals provided within said powered tissue aspiration device; andsaid hollow outer cannula is electrically conductive and said hollowouter cannula includes electrical means for maintaining said hollowouter cannula in electrical contact with a second one of said powersupply terminals conducting said RF power signal to said hollow outercannula.
 7. The powered tissue aspiration device of claim 6, whereinsaid hollow outer cannula further comprises an outer cannula baseextending from said outer cannula proximal end and being adapted forreleasably connecting with said hand-holdable housing; wherein saidhollow inner cannula further comprises an inner cannula base which isoperably associatable with said reciprocation means by way of anactuation means disposed in said hand-holdable housing andreciprocatable by said reciprocation means; and wherein said hollowinner cannula base further includes said outlet port and said continuouspassageway.
 8. The powered tissue aspiration device of claim 6, whereinsaid electrical means comprises an electrically conductive elementembedded within said outer cannula base of said hollow outer cannula. 9.The powered tissue aspiration device of claim 6, wherein said tissueaspiration operations include liposuction.
 10. A powered tissueaspiration device comprising: a hand-holdable housing provided with areciprocation means reciprocatable within said hand-holdable housing anda pair of power supply terminals for supplying a radio-frequency (RF)power signal to an electro-cauterizing cannula assembly during tissueaspiration operations, said electro-cauterizing cannula assembly beingoperably connectable to said hand-holdable housing and including ahollow inner cannula having a distal end and a proximal end and an innersuction aperture about said inner cannula distal end, said inner cannulaproximal end further including an outlet port and a continuouspassageway which communicates said inner suction aperture with saidoutlet port, a hollow outer cannula having a distal end and a proximalend and an outer suction aperture about said outer cannula distal end,said hollow inner cannula being disposed within at least a portion ofsaid hollow outer cannula while permitting aspiration of tissue throughsaid outer and inner suction apertures, along said continuous passagewayand out of said outlet port, said hollow inner cannula being operablyassociatable with said reciprocation means, and said hollow outercannula being essentially stationary with respect to said hand-holdablehousing, so as to effectuate relative sliding movement between saidhollow inner and outer cannulas when said reciprocation meansreciprocates, so that the location of said aspiration through said outerand inner suction apertures is periodically displaced, andelectro-cauterizing means associated with said hollow inner and outercannulas, for conducting said RF power signal along said hollow innerand outer cannulas and effecting coagulation of protein molecules withinthe tissue being aspirated through said outer and inner suctionapertures.
 11. The powered tissue aspiration device of claim 10, whereinsaid hollow outer cannula further comprises an outer cannula baseextending from said outer cannula proximal end and being adapted forreleasably connecting with said hand-holdable housing, wherein saidhollow inner cannula further comprises an inner cannula base which isoperably associatable with said reciprocation means by way of anactuation means disposed in said hand-holdable housing andreciprocatable by said reciprocation means, and wherein said hollowinner cannula base further includes said outlet port and said continuouspassageway, wherein said hollow inner and outer cannulas are bothelectrically non-conductive; wherein said hollow outer cannula includesan outer cauterizing electrode provided about said outer suctionaperture and first conductive means for conducting said power signalfrom the outer cannula base of said hollow outer cannula to said outercauterizing electrode; and wherein said hollow inner cannula includes aninner cauterizing electrode provided about said inner suction apertureand second conductive means for conducting said RF power signal fromsaid inner cannula base of said hollow inner cannula to said innercauterizing electrode.
 12. The powered tissue aspiration device of claim11, wherein the outer cannula base of said hollow outer cannula includesa first electrical contact element connected to said first conductivemeans, for contacting a first one of said pair of power supply terminalsprovided in said powered tissue aspiration device; and wherein the innercannula base of said hollow inner cannula includes a second electricalcontact element connected to said second conductive means, forcontacting a second one of said pair of power supply terminals providedin said powered tissue aspiration device.
 13. The powered tissueaspiration device of claim 12, wherein said first electrical contactelement is embedded within said outer cannula base of said hollow outercannula; and wherein said second electrical contact element is embeddedwithin said inner cannula base of said hollow inner cannula.
 14. Thepowered tissue aspiration device of claim 10, wherein said outer suctionaperture is elongated in the longitudinal direction of said hollow innercannula.
 15. The powered tissue aspiration device of claim 11, whereinsaid hand-holdable housing further includes a cannula cavity ofcylindrical geometry, and said inner cannula base comprises a firstcylindrical structure capable of being slidably received within at leasta first portion of said cannula cavity, and wherein a notch means isformed in said first cylindrical structure and is adapted for releasablyengaging with said actuation means.
 16. The powered tissue aspirationdevice of claim 10, wherein said tissue aspiration operations includeliposuction.
 17. A powered tissue aspiration device comprising: ahand-holdable housing provided with a reciprocation means reciprocatablewithin said hand-holdable housing and a pair of power supply terminalsfor supplying a radio-frequency (RF) power signal to anelectro-cauterizing cannula assembly during tissue aspirationoperations, said electro-cauterizing cannula assembly being operablyconnectable to said hand-holdable housing and including a hollow innercannula having a distal end and a proximal end and an inner suctionaperture about said inner cannula distal end, said inner cannulaproximal end further including an outlet port and a continuouspassageway which communicates said inner suction aperture with saidoutlet port, a hollow outer cannula having a distal end and a proximalend and an outer suction aperture about said outer cannula distal end,said hollow inner cannula being disposed within at least a portion ofsaid hollow outer cannula while permitting aspiration of tissue throughsaid outer and inner suction apertures, along said continuous passagewayand out of said outlet port, said hollow inner cannula being operablyassociatable with said reciprocation means, and said hollow outercannula being essentially stationary with respect to said hand-holdablehousing, so as to effectuate relative sliding movement between saidhollow inner and outer cannulas when said reciprocation meansreciprocates, so that the location of said aspiration through said outerand inner suction apertures is periodically displaced; andelectro-cauterizing means associated with said hollow inner and outercannulas, for conducting said RF power signal along said hollow innerand outer cannulas and effecting coagulation of protein molecules withinthe tissue being aspirated through said outer and inner suctionapertures, wherein said hollow outer cannula is adapted for releasablyconnecting with said hand-holdable housing, and wherein said hollowinner cannula is operably associatable with said reciprocation means byway of an actuation means disposed in said hand-holdable housing andreciprocatable by said reciprocation means.
 18. The powered tissueaspiration device of claim 17, wherein said hand-holdable housingfurther includes a cannula cavity of cylindrical geometry, and saidinner cannula base comprises a first cylindrical structure capable ofbeing slidably received within at least a first portion of said cannulacavity, and wherein a notch means is formed in said first cylindricalstructure and is adapted for releasably engaging with said actuationmeans, and wherein said outer cannula base comprises a secondcylindrical structure capable of being received within at least a secondportion of said cannula cavity, and wherein a flange portion extendsfrom said second cylindrical structure an is adapted for releasablyengaging with a matched recess formed in said cannula cavity.
 19. Thepowered tissue aspiration device of claim 17, wherein said tissueaspiration operations include liposuction.
 20. An electro-cauterizingcannula assembly for use with a powered tissue aspiration device havinga hand-holdable housing provided with a reciprocation meansreciprocatable within said hand-holdable housing and a pair of powersupply terminals for supplying a radio-frequency (RF) power signal tosaid cannula assembly during tissue aspiration operations, saidelectro-cauterizing cannula assembly being operably connectable to saidhand-holdable housing and comprising: a hollow inner cannula having adistal end and a proximal end and an inner suction aperture about saidinner cannula distal end, said inner cannula proximal end furtherincluding an outlet port and a continuous passageway which communicatessaid inner suction aperture with said outlet port, a hollow outercannula having a distal end and a proximal end and an outer suctionaperture about said outer cannula distal end, said hollow inner cannulabeing disposed within at least a portion of said hollow outer cannulawhile permitting aspiration of tissue through said outer and innersuction apertures, along said continuous passageway and out of saidoutlet port, said hollow inner cannula being operably associatable withsaid reciprocation means, and said hollow outer cannula beingessentially stationary with respect to said hand-holdable housing, so asto effectuate relative sliding movement between said hollow inner andouter cannulas when said reciprocation means reciprocates, so that thelocation of said aspiration through said outer and inner suctionapertures is periodically displaced, and electro-cauterizing meansassociated with said hollow inner and outer cannulas, for conductingsaid RF power signal along said hollow inner and outer cannulas andeffecting coagulation of protein molecules within the tissue beingaspirated through said outer and inner suction apertures; wherein saidhollow inner cannula further comprises a cannula keying means formaintaining said hollow inner and outer cannulas in a predeterminedaxial alignment so that said outer suction aperture is in registrationwith at least a portion of said inner suction aperture as said hollowinner and outer cannulas are caused to undergo said slidable movement.21. The powered tissue aspiration device of claim 20, wherein saidhollow outer cannula further comprises an outer cannula base extendingfrom said outer cannula proximal end and being adapted for releasablyconnecting with said hand-holdable housing; wherein said hollow innercannula further comprises an inner cannula base which is operablyassociatable with said reciprocation means by way of an actuation meansdisposed in said hand-holdable housing and reciprocatable by saidreciprocation means; and wherein said hollow inner cannula base furtherincluding said outlet port and said continuous passageway.
 22. Thepowered tissue aspiration device of claim 20, wherein said tissueaspiration operations include liposuction.
 23. A powered tissueaspiration device comprising: a hand-holdable housing provided with areciprocation means reciprocatable within said hand-holdable housing anda pair of power supply terminals for supplying a radio-frequency (RF)power signal to an electro-cauterizing cannula assembly during tissueaspiration operations, said electro-cauterizing cannula assembly beingoperably connectable to said hand-holdable housing and including ahollow inner cannula having a distal end and a proximal end and an innersuction aperture about said inner cannula distal end, said inner cannulaproximal end further including an outlet port and a continuouspassageway which communicates said inner suction aperture with saidoutlet port, and a hollow outer cannula having a distal end and aproximal end and an outer suction aperture about said outer cannuladistal end, said hollow inner cannula being disposed within at least aportion of said hollow outer cannula while permitting aspiration oftissue through said outer and inner suction apertures, along saidcontinuous passageway and out of said outlet port, said hollow innercannula being operably associatable with said reciprocation means, andsaid hollow outer cannula being essentially stationary with respect tosaid hand-holdable housing, so as to effectuate relative slidingmovement between said hollow inner and outer cannulas when saidreciprocation means reciprocates, so that the location of saidaspiration through said outer and inner suction apertures isperiodically displaced; electro-cauterizing means associated with saidhollow inner and outer cannulas, for conducting said RF power signalalong said hollow inner and outer cannulas and effecting coagulation ofprotein molecules within the tissue being aspirated through said outerand inner suction apertures; a RF power signal generator for generatingsaid RF power signal; and a flexible cable for conducting said RF powersignal and supplying said RF power signal to said powered tissueaspiration device.
 24. The powered tissue aspiration device of claim 23,wherein said hollow outer cannula further comprises an outer cannulabase extending from said outer cannula proximal end and being adaptedfor releasably connecting with said hand-holdable housing, wherein saidhollow inner cannula further comprises an inner cannula base which isoperably associatable with said reciprocation means by way of anactuation means disposed in said hand-holdable housing andreciprocatable by said reciprocation means, and wherein said hollowinner cannula base further including said outlet port and saidcontinuous passageway, and wherein said hollow outer cannula furthercomprises an outer cannula base which extends from said inner cannulaproximal end and is adapted for releasably connecting with saidhand-holdable housing and, wherein said electro-cauterizing cannulaassembly comprises first, second and third pairs of said outer and innersuction apertures, each said pair of suction apertures being at leastpartial registration when said hollow inner cannula is inserted withinsaid hollow outer cannula.
 25. The powered tissue aspiration device ofclaim 23, wherein said tissue aspiration operations include liposuction.26. The powered tissue aspiration device of claim 23, wherein said outersuction aperture is elongated in the longitudinal direction of saidhollow inner cannula.
 27. The powered tissue aspiration device of claim24, wherein said hollow outer cannula is electrically non-conductive andincludes a cauterizing electrode provided about said hollow outersuction aperture; and wherein said hollow inner cannula is electricallyconductive and said hollow inner cannula base includes electrical meansfor conducting said RF power signal from one of said power supplyterminals to said hollow inner cannula.
 28. The powered tissueaspiration device of claim 27, wherein said electrical means comprises adevice inserted within the outer cannula base of said hollow outercannula and having an electrical contact element for conducting said RFpower signal from one of said power supply terminals to said hollowinner cannula while said hollow inner cannula is being reciprocatedwithin said hollow outer cannula.
 29. The powered tissue aspirationdevice of claim 24, wherein said outer cannula base includes anelectrical contact element for establishing electrical contact with oneof said power supply terminals.
 30. The powered tissue aspiration deviceof claim 24, wherein said hollow inner cannula is electricallynon-conductive and includes a cauterizing electrode provided about saidinner suction aperture and the inner cannula base of said hollow innercannula includes an electrical connection element of electricallyconnecting said cauterizing electrode with a first one of said powersupply terminals; and said outer cannula is electrically conductive andhas an outer cannula base and said hollow outer cannula base includeselectrical means for maintaining said hollow outer cannula in electricalcontact with a second one of said power supply terminals and conductingRF power signal to said hollow outer cannula.
 31. The powered tissueaspiration device of claim 27, wherein said electrical means comprisesan electrically conductive element embedded within the outer cannulabase of said hollow outer cannula.
 32. The powered tissue aspirationdevice of claim 24, wherein said hollow inner and outer cannulas areboth electrically non-conductive; wherein said hollow outer cannulaincludes an outer cauterizing electrode provided about said outersuction aperture and first conductive means for conducting said RF powersignal from the outer cannula base of said hollow outer cannula to saidouter cauterizing electrode; and wherein said hollow inner cannulaincludes an inner cauterizing electrode provided about said innersuction aperture and second conductive means for conducting said RFpower signal from said hollow inner cannula base to said innercauterizing electrode.
 33. The powered tissue aspiration device of claim32, wherein the outer cannula base of said hollow outer cannula includesa first electrical contact element connected to said first conductivemeans for contacting a first one of said power supply terminals; andwherein said hollow inner cannula base includes a second electricalcontact element connected to said second conductive means for contactinga second one of said power supply terminals.
 34. The powered tissueaspiration device of claim 33, wherein said first electrical contactelement is embedded within said hollow outer cannula base; and saidsecond electrical contact element is embedded within said hollow innercannula base.
 35. The powered tissue aspiration device of claim 23,wherein said outer suction aperture is elongated in the longitudinaldirection of said hollow inner cannula, and said inner suction apertureis substantially shorter than said outer suction aperture along saidlongitudinal direction.
 36. The powered tissue aspiration device ofclaim 23, wherein said hand-holdable housing further includes a cannulacavity of cylindrical geometry, and said hollow inner cannula basecomprises a first cylindrical structure capable of being slidablyreceived within at least a first portion of said cannula cavity, andwherein a notch means is formed in said first cylindrical structure andis adapted for releasably engaging with said actuation means.
 37. Thepowered tissue aspiration device of claim 36, wherein said outer cannulabase comprises a second cylindrical structure capable of being receivedwithin at least a second portion of said cannula cavity, and wherein aflange portion extends from said second cylindrical structure and isadapted for releasably engaging with a matched recess formed in saidcannula cavity.
 38. The powered tissue aspiration device of claim 23,which further comprises a cannula keying means for maintaining saidhollow inner and outer cannulas in a predetermined axial alignment sothat said outer suction aperture is in registration with at least apotion of said inner suction aperture as said hollow inner and outercannulas are caused to undergo said slidable movement.
 39. The poweredtissue aspiration device of claim 23, which further comprises first,second and third pairs of said outer and inner suction apertures, eachsaid pair of suction apertures being at least partial registration whensaid hollow inner cannula is inserted within said hollow outer cannula.40. The powered tissue aspiration device of claim 23, wherein said a RFpower signal generator is realized as a device, external to saidhand-holdable housing, for generating said RF power signal.
 41. Thepowered tissue aspiration device of claim 40, wherein said flexiblecable conducts said RF power signal from said external device to saidpower supply terminals in said power hand-holdable housing.
 42. Thepowered tissue aspiration device of claim 23, which further comprises acontrol means including a manually actuated trigger integrated with saidhand-holdable housing.